1. Technical Field
The present invention relates generally to a composite beam apparatus that is configured to have an electron beam column and a focused ion beam column, and to form and observe a cross section of a sample.
2. Description of the Related Art
As well known to those skilled in the art, a FIB-SEM apparatus equipped with a focused ion beam column configured to irradiate a focused ion beam (FIB) onto a sample to form a cross section has been used as a scanning electron microscope (SEM). As a result, an electron beam is irradiated from the SEM to a cross section processed by the focused ion beam, whereby cross section processing of the sample, and observation and measurement of the cross section can be carried out in situ in one apparatus.
In addition, a technique for finish processing has been developed, wherein a third beam column that irradiates a gas ion beam having lower energy such as argon compared to the focused ion beam column is installed at the FIB-SEM apparatus, and the processing-damaged layer generated on the surface of the sample due to FIB processing is irradiated with the gas ion beam and removed (Patent Document 1).
In particular, in recent years, there are many cases in which it is required to determine the end point of cross section processing of the sample in a state in which a specific pattern is exposed, so it is necessary to determine the processing end point while observing by the SEM the processing surface (cross section) during processing with the gas ion beam.